I used to do it all the time over summer breaks for Everquest, Day of Defeat (once played day of defeat with my cousin for 26 straight hours), KOTOR for Xbox, Forza 2, Diablo 2 (again with cousin). My fiance is pissed at me because i miss pulling them all nighters for games and I told her when Fallout 3 comes out, its gonna happen.
My greatest moment during all-night gaming. Me and my cousin were playing Everquest, we were on hour 22 straight i think, fueld by beer and mountain dew, and back then you could drop money on the ground (to get rid of weight for the monks). Anyways we on a boat, and my guy is drunk in game too, and drops a copper coin off the side, me and him think we need it back and next thning you know we jump off and the screw does a blue vortex thing and we have to petition GM. When they got us out, we said thanks and tried giving him in-game ale that i crafted myself. Just the ridiculousness of it all involving a copper coin and the sleep depervation... one of those you had to be there